This article describes how to split a linestring or a multilinestring using PL/SQL at a known point.
This post documents GeoRaptor’s Metadata Tool that can be used to created, update, delete and analyze the xxx_GEOM_METADATA associated with data held in tables and SDO_GEOMETRY columns.
Introduction The ordinates stored in an geometry objects, across all spatial data types do not have any rounding applied to their values. This is one aspect of data management that is seldom considered by most practitioners. Other articles in this website deal with how to round their values. This article is about a related topic”Read More
Introduction All database spatial types that I have worked with have constructors based on Well Known Text (WKT). When constructing a geometry all those types check the WKT’s structure. So, for example, the polygon below is wrong for two reasons: 1. It does not have its exterior ring correctly defined (eg “POLYGON((…))” ; 2. ItRead More
1. Solutions Architecture. I discovered over the years that I am a pretty good systems and solutions architect. How does this apply to you? Well, let’s say you have a business problem you want to be solved. You have a bunch of technology options that provide a framework (or constraint) for delivery, and want toRead More
Sometimes it is a data quality requirement for linear data (roads, pipelines, transmission lines) that curves within the lines must have a radius greater than a particular amount. Recently a customer asked me to write some TSQL functions to help them run data quality checks over linear data loaded into a SQL Server 2008 geometryRead More
The background to this blog comes from two separate sources: the first is my testing of SQL Server 2008 “Katmai”, and secondly, a blog article that Charlie Savage wrote a while back on The Sad State of GIS Web Standards. Web Mapping Standards As an ex-GIS Manager who monitored GIS standards for possible deployment withinRead More
Comment: This article was written about 10 years ago. Most of what is written is still relevant though the comments about disk usage and access do not apply if SSD is being used. Introduction There are lots of things one can do to improve performance in mapping environments because of a lot of the visualisationRead More
This article demonstrates the power of database-based spatial processing. The business requirement is to determine, dynamically, the side of a land parcel that faces the street (could be single 2 point straight line to something more complex), and then determine the clockface direction from either ends of the frontage or the middle, to a object in the roads reserve (eg telecommunications pit).
This article shows how to create a GeoJSON Document from Selection of SDO_Geometry objects.